Browsing by Author "Tsai, M. Y."

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Automatic Control System for Thermal Comfort Based on Predicted Mean Vote and Energy Saving
(2015-01-01)
Ku, K. L.
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Liaw, J. S.
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Tsai, M. Y.
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Liu, T. S.
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機械工程學系
For human-centered automation, this study presents a wireless sensor network using predicted mean vote (PMV) as a thermal comfort index around occupants in buildings. The network automatically controls air conditioning by means of changing temperature settings in air conditioners. Interior devices of air conditioners thus do not have to be replaced. An adaptive neurofuzzy inference system and a particle swarm algorithm are adopted for solving a nonlinear multivariable inverse PMV model so as to determine thermal comfort temperatures. In solving inverse PMV models, the particle swarm algorithm is more accurate than ANFIS according to computational results. Based on the comfort temperature, this study utilizes feedforward-feedback control and digital self-tuning control, respectively, to satisfy thermal comfort. The control methods are validated by experimental results. Compared with conventional fixed temperature settings, the present control methods effectively maintain the PMV value within the range of and energy is saved more than 30% in this study. Note to Practitioners-For advanced control of unitary air conditioners in rooms, air conditioners may have to be retrofitted or connected with extra devices by wire connection, whose processes may be difficult for users, and inappropriate installation may damage original air-conditioning units. This study hence presents a noninvasive method for indoor thermal comfort with a wireless sensor network. The present method facilitates hardware implementation without changing interior devices of the air conditioner. The wireless sensor network measures temperature, air velocity, and humidity around occupants and further transmits temperature commands for air conditioner control. Based on the measured data, a PMV model is adopted to evaluate thermal comfort. Using an inverse PMV model with feedforward-feedback control and self-tuning control, respectively, this study aims to automatically maintain human thermal comfort as well as save energy. The ANFIS model and a particle swarm algorithm are used to solve the inverse PMV model and determine the thermal comfort temperature. Based on that temperature, feedforward-feedback control, and self-tuning control are used to determine appropriate temperature settings in the air conditioner so as to change the cooling capacity and maintain thermal comfort. Experimental results show that the present control method can maintain thermal comfort and saves 30% more energy than the conventional method.
Molecular Dynamics insight into the role of tertiary (foldon) interactions on unfolding in Cytochrome c
(2009-06-16)
Tsai, M. Y.
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Morozov, A. N.
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Chu, K. Y.
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Lin, S. H.
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交大名義發表
Hydrogen exchange experiments reveal the existence of a foldon structure in Cytochrome c. We performed constant temperature Molecular Dynamics simulations of Cytochrome c to investigate the macroscopic behavior of the foldons. The results showed that the tertiary interactions in Cytochrome c play an important role in the stabilization of the N- and C-terminal helices. We also observed the macroscopic behavior of a black foldon in the process of thermal unfolding. Our results support that Cytochrome c folding occurs in accordance with the classical pathway concept of Levinthal. (c) 2009 Elsevier B.V. All rights reserved.
Nonadditive interactions in protein folding: The Zipper model of cytochrome c
(2007-08-01)
Morozov, A. N.
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Shiu, Y. J.
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Liang, C. T.
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Tsai, M. Y.
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Lin, S. H.
Hydrogen exchange experiments (Krishna et al. in J. Mol. Biol. 359:1410, 2006) reveal that folding-unfolding of cytochrome c occurs along a defined pathway in a sequential, stepwise manner. The simplified zipper-like model involving nonadditive coupling is proposed to describe the classical "on pathway" folding-unfolding behavior of cytochrome c. Using free energy factors extracted from HX experiments, the model can predict and explain cytochrome c behavior in spectroscopy studies looking at folding equilibria and kinetics. The implications of the proposed model are discussed for such problems as classical pathway vs. energy landscape conceptions, structure and function of a native fold, and interplay of secondary and tertiary interactions.
Study of Thick Copper Metallization with WNx as Diffusion Barrier for AlGaN/GaN HEMTs
(2019-01-01)
Lin, Y. C.
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Lee, M. W.
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Tsai, M. Y.
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Wang, C.
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Yao, J. N.
In this study, the thick copper metallization with WNx as diffusion barrier is investigated for AlGaN/GaN HEMTs. The device current density, transconductance, ft, fmax, noise figure were evaluated for the device with and without thick copper interconnect metal, and the thermal stability test was performed after the device with copper metallization.